A CT scan is one of many imaging tests your doctor may use to investigate problems with your spine, such as pain due to injuries, disease, or infection. Your doctor might order a lumbar CT scan for a variety of symptoms and / or condition back pain accompanied by fever, birth defects affecting the spine, a herniated disk, infection, injury to the lower spine, low back pain, multiple sclerosis, osteoarthritis, a pinched nerve, problems controlling the bladder, signs of cancer, spinal surgery preparation, numbness, or other problems with your legs.